Lock washer



April 21, 1931- H. D. BOWMAN 1,801,999

LOCK WASHER Filed Oct. 15, 1927 ATTORNEYS.

Patented Apr. 21, 1931 UNITED STATESPATENT' OFFICE EYMAN D. BOWMAN, OF PITTSBURGH, PENNSYLVANIA LOCK WASHER Application filed October 15, 1927. Serial No. 226,294.

This invention relates to bolt and nut washers and more in particular to lock-washers.

The primary object of this invention is to provide a resilient washer which will exert a continuous pressure upon the bolt-nut, thus preventing said nut from working loose. Another object of this invention is the provision of a lock-washer adapted to engage the shank of the bolt as well as the nut thereof, to provide double locking means against relative movement between the bolt and nut. A further object of this invention is to provide a lock-washer having the above features and which is well adapted, owing to its simplicity, g I

ends forced toward the center of the washer,

to be manufactured by the stamping process. Additional features and advantages of this invention will appear in the course of the following description considered in connection with the accompanying drawing forming a part of this application, and in which:

Fig. 1 is a fragmentary view, partly shown in section, illustrating a bolt and nut locked by a lock-washer of my invention.

Fig. 2 is a top plan view of the lock-washerused in Fig. 1.

n Fig. 3 is a top. plan view of a modified washer.

Fig. 4 is a similar view showing another modification.

Fi 5 shows a modi cation.

i Fig. 6 is a fragmentary perspective view corresponding to .Fig. 3.

Fig. 7 is a showing afront elevation of the peripheral gripping means .shown in Figs. 3 and 6. Fig. 8 is a fragmentary perspective view L showing a resilient nut-holding lug applica- 40 ble to any desired type of lock-washer of my invention, and especially shown in Fig. 5. Fig. -9 is a detail view showing in elevation two of the.bolt engaging fingers, between lines 9-9, Fig. 2.

Referring to the drawing, a lock-washer made according to my invention consists of a disc 1 having a central aperture 2 adapted to fit snugly about the threaded shank of the bolt to which it is applied. Radial slots 3, 50 of suitable length, are provided to divide the top plan'view of still another fragmentary view of a view inner portion of the washer into any desired number of sector-shaped fingers 4.

As shown in the various figures, these fingers are provided intermediate their inner ends and places of attachment to the main body of the disc with concentrically arranged concavo-convex bends5 which are adapted to be engaged by the underside of the bolt-nut. These fingers are also bent transversely at an angleto fit the threads of the bolt at one side thereof, as shown in Fig. 9.

It will be readily understood that, when the bends 5 are compressed by the nut, the finers 4 will be straightened and their inner thus causing said inner ends to exert a rightangularly directed pressure against the shank of the bolt; and the radial, upper, edges 6 of the transversely bent portions of the fingers will dig into the underside of the nut, while the lower, opposite, radial edge 7 of each finger will cut into the bolted element.

At the same time, the spring effect of these flattened fingers will force the nut into close engagement with the threads of the'nut, thus providing several simultaneously operating means to prevent the accidental loosening of the nut'on said bolt.

In Figs. 5 and 8 is shown a washer having a substantially U-shaped, resilient, 111g 8 which is designed to press against the-flats of the nut. If, 'desired, two or more such lugs could, of course, be provided. Owing to the elasticity of this lug, the free upwardly directed inner end 9 of this lug mayisnap over the corners of a polygonal nut, as the latter is being screwed down on the bolt.

Another method of further pneventing the loosening of the nut or bolt is shown in Figs. 3, 6 and 7, in which upwardly and downwardly directed resilient lugs 10, 11 are formed in the outer periphery of the washer. These lugs have s an edges which respectively di into the un erside of the nut and the ad acent element which is to be secured by the olt. If desired, the lugs 10 and 11 may be used in combination with any one of the alternative constructions shown in the drawing. It 'willlbe noted, in Fig. 7

than the top ofthe bends and that the latter will have to be flattened partly by the nut portion of said b0 t.

outer ends substantiall before said lugs will become effective; this is done in order to reduce the length of said lugs to the proper amount to produce a strong sprin action.

Alt ough the washers built according to this invention are intended to be made of resilient material it may happen that they will lose part, or all, of their springiness after prolonged application. In such a case, it would be ractically impossible to remove a washer without cutting it in pieces, because of the spring-fingers digging into the threads of the-bolt, and at one side thereof even reaching dowirto the root of said threads. contingcncynray be taken care of by making the washer, from the beginning, in two semicircular parts 12 and 13 se arably joined together by avdovetail conn ction 14. To remove a flattened, so-eallcd dead washer, all that is necessary to be done is to separate the two halves of the washers by prying them off by meansrof a screw-driver or knife, as will be readily understood.

While I have illustrated and described herein difierent embodiments of my invention, as applied to washers of circular shape, it may be found advisable after continued experience to make additional modifications in the construction or shape thereof, and I intend to include in this application all such variations which fall within the scope of the appended claims.

I claim:

1. In a nut lock comprising a flat plate havin an aperture adapted to be engaged by a olt, a plurality of radially disposed sector-like fingers arranged side by side about Said aperture and twisted transversely; said fingers having intermediate their inner and outer ends substantiall semi-circular concavo-convex portions a apted to be engaged and flattened by the nut to be locked, whereby said fingers are caused to exert a rectangularly directe d ressure against the body 2. \In a nut lock comprising a flat plate having an aperture adapted to be engaged by a olt, a plurality of radially disposed sector-like fingers arranged side by side about said aperture and twisted transversely; said fingers having intermediate their inner and semi-circular concavo-conyex ortions a apted to be engaged and flattened y the nut to be locked, whereby This about said aperture and twisted transversely; said fingers having intermediate their inner and outer ends substantially semi-circular concavo-convex portions adapted to be engaged and flattened b the nut to be locked, an a substantially al -shaped resilient lug positioned peripherally on said nut-lock.

4. In a nut lock comprisin a flat plate havin an a erture adapted to e engaged by a be t, a p urality of radiallg dis osed sectorlike fingers arranged side y si e about said aperture and twisted transversely; said fingers having intermediate their inner and outer ends substantiallsemi-circular concave-convex portions a apted to be engaged and flattened by the nut to be locked, and a,

plurality of alternately up and downwardly 4 directed radial lugs formed at the outer periphery of said nut lock, also adapted to be flattened by said nut.

5. In a nut lock comprisin a flat plate having an aperture adapted tobe engaged by a bolt, a plurality of radially dis osed sectorlike fingers arranged side by si e about said aperture and twisted transversely; said fingers having intermediate their inner and outer ends substantiall semi-circular concave-convex portions a apted to be enga ed andflattened by the nut to be locked, an a pluralifly of alternately up and downwardly directe radial lugs formed at the outer periphery of said nut lock also adapted to be engaged by said nut; said radial lugs bein of lesser height than the raised portion 0 said fingers.

In testimony whereof I aflix 111 Si nature.

HYMAN D. B W AN.

- said fingers are caused to exert a rectangularly'directed pressure against the body portion of said bolt; the angle of twist on said fingers corresponding substantially to the a le ofthe threads on on; side of said bolt.

In a nut lock comprising a flat plate havingoan aperture adapted to'be engaged by a It, a plurality of radially disposed sector-like fingers arranged side by side 

